Medium-size race fit jersey fits me perfectly across the chest and shoulders, but is very tight around the waist (I have 32-33in waist). The gilet is also a race fit across the upper torso, but tight around the waist, although not as tight. Large would be loose and flappy, even in the race fit. Basically, it's all tighter than a DHB medium, but fits me anyway. I am 6ft, slim build, middle-aged paunch under control (as in, barely there ... yet).
Arm warmers in M are a perfect fit, as is the T-shirt.
I didn't buy a mug.